So, I realize that the stated diameter in a particular caliber is nominal. Usually a 7.62 caliber actually has ~7.82mm diameter. Most 7mm bullets are closer to a diameter of 7.2mm, and most 6.8mm bullets are about 7.0mm. The 5.56 NATO shoots a 5.7mm diameter bullet. Even the metric/NATO designation of the .50 BMG (actual diameter = .510") is 12.7x99, instead of showing the more accurate 12.95mm. I notice that many rifle bullets are given names that make them seem between about 1 and 3 tenths of a millimeter smaller than they really are. And this isn't a purely Western tendency; the Soviet 5.45x39mm is really a 5.6mm diameter, the Chinese 5.8x42mm is supposed to have a diameter of 6.0mm, and the old Japanese 6.5x50 has an actual diameter of ~6.7mm. Is there a reason for this nominal diminution of rifle bullets?
I had this crazy thought that such specifications might be indicative of the diameter of the bullet's lead core's diameter before the jacket went on. Any thoughts, anecdotes or facts?
And just for those who might know, why is this sometimes the opposite in pistol bullets (.44 cal = .430", .38/.380 = .355"-.357", .32 = .312")?
I had this crazy thought that such specifications might be indicative of the diameter of the bullet's lead core's diameter before the jacket went on. Any thoughts, anecdotes or facts?
And just for those who might know, why is this sometimes the opposite in pistol bullets (.44 cal = .430", .38/.380 = .355"-.357", .32 = .312")?